“A most interesting finding was that the higher risk was the same for both sweetened and artificially sweetened beverages, suggesting that greater risk of diabetes was not directly related to higher calorie intake, or adverse metabolic effects of sugar (in the form of sucrose) from the sweetened drinks,” said Professor Christine Williams, Professor of Human Nutrition, University of Reading.

Last year, a study by Harvard University suggested that two cans of fizzy pop could increase the risk of heart attacks and strokes.

The study found the drinks raised the risk of heart attacks by one third and the risk of strokes by one sixth.

Other studies have linked sugary drinks to a raised risk of prostate cancer.

A 15-year study found those drinking 300ml of fizzy drinks daily had a 40 per cent higher chance of the disease.

Earlier this week, a study found women who regularly consume soft drinks may be reducing their chances of getting pregnant.

The study of 524 patients found a link between artificial sweeteners, such as those used in “diet” sodas, and lower fertility rates, while use of sugar in soft drinks and added to coffee was associated with poorer quality of eggs and embryos.

One of Britain’s leading fertility experts described the findings as “highly significant”, and warned women not to underestimate the effects of food additives on their likelihood of conception.